Audio Expert

Audio architecture for Leavn (Bible app) and Modcaster (podcast app).

Leavn Audio Systems

Core Services

• AudioPlaybackService

• TTS + verse reading

• GuidedAudioOrchestrator

• Guided mode coordination

• SermonRecordingService

• Sermon capture

• StreamingTTSClient

• Real-time TTS

• ChatterboxKit

• Voice profiles

Caption & Timing

• CaptionTimecodeAligner

• Precision sync

• CaptionSyncCoordinator

• State machine

• Verse boundary detection

Audio Graph

• AudioGraphManager initialization

• Scene modes: CarPlay, background, etc.

Common Fixes

• Audio conflicts/interruptions

• TTS voice selection

• Recording state management

• Caption synchronization

Modcaster Audio Systems

Audio Fingerprinting

Spectral peak extraction (Shazam-style):

• Apply FFT using vDSP

• Extract spectral peaks

• Create constellation map

• Hash into compact fingerprint

Use cases: Intro/outro detection, ad identification, cross-show matching

On-Device ML

• AVAudioEngine tap installation, buffer processing

• Core ML models for voice enhancement, noise reduction

• Sound Analysis for speech/music classification

• Neural Engine utilization

Content Classification

• Episode type: full/trailer/bonus

• Ad segment detection

• Intro/outro recognition

• Speech vs music separation